Field of the Invention
This disclosure relates to devices and methods, which can be used alone or in combination, to identify and monitor changes of a suspect area on a patient, for example dermatological changes.
Description of the Related Art
There are many reasons why a medical professional, patient, or both would want to monitor changes on an exterior or internal surface of a patient. For a suspect area, especially one that may indicate some form of skin cancer, it is important to detect and treat the area in its early stages. One type of skin cancer is known as melanoma, which is a malignant cancer of the pigment cells (melanocytes). Other forms of skin cancer also exist and are known as basal and squamous cell cancers, which are tumors of unpigmented cells (keratinocytes) of the skin.
Melanocytes occur at various depths within the epidermal (upper) and dermal (lower) layers of skin. Melanocytes are normally distributed in the layers of the skin and produce pigment in response to being subjected to ultraviolet light (e.g., sunlight). Aggregated melanocytes are termed naevus cells and can be indicative of a melanoma. Because a melanoma may appear as a mole, medical professionals typically attempt to ascertain whether the suspicious area is changing over time. Identifying changes early typically results in a rapid diagnosis, which in turn often leads to rapid and highly effective treatments that can greatly increase the patient's survival rate and in most cases, complete recovery.
Historically, the standard of care for screening or monitoring melanoma is a visual inspection or visual comparison of photographs by a medical professional. These visual inspections or comparisons are subjective and do not enable the medical professional to detect small or subtle changes in a suspect area. Changes in the perimeter, depth, shape, and even color of a melanoma can be subtle for a time and then progress rapidly. Moreover, changes in the color or perimeter, for example, of a melanoma are not easily discernable to the human eye so these changes may go unnoticed for a long period of time.
In U.S. Pat. No. 6,427,022, issued to Craine et al., a skin lesion is monitored by obtaining a series of digital baseline images over time and comparing these images. The method of comparison taught in Craine et al. is that the baseline image is compared visually by the viewer with a subsequently obtained image by alternately displaying the respective images, in a blinking fashion. The blinking action is created by quickly alternating the images with respect to one another on a display monitor to enable the viewer to detect changes in the skin lesion.
Even though the standards of care discussed above may involve images, each standard of care suffers from the subjectivity and uncertainty associated with the medical professional trying to ascertain changes in a suspicious area by visual comparison. The visual comparison methods are subjective and less accurate for a number of reasons. For instance, the medical professional may be inexperienced, may have been distracted during the examination, or may have selected the wrong location on the patient's body during a follow-up examination.
Therefore, a more effective, less subjective, and low-cost approach for at least monitoring changes in a suspect area is desirable.